PVWatts v.2 can be run from either NREL's IMS PVWatts v.2 site or NREL's IMS US Solar Atlas. The Solar Atlas is somewhat more complicated, but provides more capability in identifying features and it can provide elevation coverage as well as the solar resource available for 14 collector types (lower 48 only). Both sites allow the user to zoom in and click a location, or to type in and zoom to a user specified Latitude/Longitude or Zip Code. Reference features include counties, roads, interstates and places/cities. An on-line help page can be accessed through the icon. If you only need PV system performance, the IMS PVWatts v.2 site is easier to use.

• On a PC the Internet Map Server works best with Microsoft Internet Explorer.

Other browsers partially or fully supporting the IMS on a Macintosh computer are:
• Netscape v.8.1.2 - fully supported.


• Firefox v.3.0.2 - supported.


• On a Macintosh computer you are advised to run the Internet Map Server through Apple Computer, Inc.'s Safari browser.
  Other browsers partially or fully supporting the IMS on a Macintosh computer are:
  • Microsoft Internet Explorer - fully support; however, extra explanatory text appears below the layers list in the Layers window (right-hand side of the browser windw.)
  
  
  • Mozilla Firefox v.2.0.0.11 - fully supported.
  
  
  • Netscape v.7.2 - fully supported.
  
  
  • Mozilla v.1.7.8 - - fully supported.

• Important! If you have enabled a pop-up blocker you will need to add mapserve2.nrel.gov and rredc.nrel.gov to the blocker's list of sites from which pop-ups are allowed. Check under your browser's Tools menu for pop-up blocker options.

For questions, comments or suggestions regarding NREL's IMS PVWatts v.2 site please email the IMS Administrator.

• Launching PVWatts v.2
  • Directions for Launching PVWatts v.2 on NREL's Internet Map Server (IMS)
  • Directions for Launching PVWatts v.2 on NREL's IMS Solar Altas:

    If you are not familiar with PVWatts v.2 and the Internet Map Server follow these directions to run the calculator:

    1. To start PVWatts v.2 go to the United States Solar Atlas. (This link will open a new browser window for PVWatts v.2 so that you can still access the directions in your present window.)

    2. On-line help is available via the open book icon ( )located at he top of the window and a little to the right.

    3. Layers or coverages available for rendering are listed in the right-hand pane; cick the "layers" icon beside a data list title to expand that list; e.g., Lower 48 Reference Data. Check the boxes beside the coverages you wish to have rendered. Click the Refresh Map button at the bottom of the pane to render the selected layers. The features in these layer (e.g., roads, lakes) can help you locate the geographics area in which you are interested on the map.

       Please note that the number of layers to be rendered can adversly affect load time for the map. Layers for rendering can be selected at any time during IMS session.

    4. Zoom in to the area of the map in which you are interested using the Zoom-In () and Pan () tools.
    5. Clicking on the title of a layer (e.g., ZIP Codes for all U.S. under Lower 48 Reference Data) will make that the active layer. Activating the Identity tool (), then clicking anywhere on the map will bring up a small text box below the map listing the information that has been requested through this action (e.g., ZIP Code, post office name and state.)
    6. Select the PVWatts icon above the map, then click on the map at the location you've chosen.
    7. A new brwoser window will open loaded with a form which identifies the grid cell you chose, and which asks for information regarding the PV system for which you wish to run the calculator. The fields are filled in with the PVWatts default system values and the average electric rate for the cell you chose. You may change any of these values before running the calculator.
    8. Click the "Calculate" button to run the calculator for the values you've entered.